The invention relates to a retractable ventilation system for a household appliance as well as a household appliance having at least one such ventilation system. The invention also relates to a method for operating the ventilation system.
Retractable tabletop ventilation systems are known which work like extractor hoods but can be recessed into a surface (e.g. a kitchen worktop or a table). Typically retractable tabletop ventilation systems are disposed in the immediate vicinity of a cooktop, from the operator's perspective generally behind the cooktop. Such retractable tabletop ventilation systems are frequently also referred to as downdraft extractors. Thus it is possible that e.g. during cooking the retractable tabletop ventilation system is extended and then retracted again as soon as it is no longer required. The retractable tabletop ventilation system can for example comprise a suction housing or an air intake, either of which can be extended for suction.
It is known for the retractable tabletop ventilation system to be operated with a single button, which when operated once extends the system and when operated afresh retracts it again. Certain safety criteria have to be satisfied here, so that the possibility of trapping e.g. a hand or a finger in the retractable tabletop ventilation system when it is being retracted is effectively prevented.
In this respect it is known for operation to be implemented by means of the single button incorporating safety circuits using microcontrollers or integrated semiconductor components. However, the disadvantage of this is that the safety circuits are configured separately from the actual actuation of the lifting motor. A further disadvantage is that this solution is relatively expensive, because firstly a microcontroller with corresponding programming is required and secondly the safety circuits with associated actuation must be provided.